fear around failing and ruining marriage

My husband has complained for over a decade about my reaction when we start fighting. I overreact, exaggerate, deflect, deny the situation and try to hide. I don’t know why I do this repeatedly as it leads to us not speaking for days and sometimes contemplating divorce. He’s asked me for 15 years to stop engaging in these behaviors and accept responsibility for my actions. He’s begged for me to stop when I start doing the above, but it’s like my toddler brain takes over and I feel so unheard that I can’t seem to stop myself. Before I know it, we are in another horrid fight and I’m looking at apartments envisioning a terrible lonely life. Neither one of us want to get divorced, we both agree we want things to work out, but I feel out of control when these fights happen. How do I get enough control that my toddler brain isn’t running the show?